Surplus munitions, including bulk explosives, such as Composition B present a problem for the US military. Current budget constraints force the US military to prioritize its spending while effectively defending the interests of the United States. Defense budgets are further tightened because aging and surplus munitions must be guarded and stored. The US military regularly destroys a significant amount of its surplus munitions each year in order to meet its fiscal challenge. It also must destroy a significant amount of munitions each year due to deterioration or obsolescence.
In the past, munitions stocks have been disposed of by open burn/open detonation (OBOD) methods—the most inexpensive and technologically simple disposal methods available. Although such methods can effectively destroy munitions, they fail to meet the challenge of minimizing waste by-products in a cost effective manner. Furthermore, such methods of disposal are undesirable from an environmental point of view because they contribute to the pollution of the environment. For example, OBOD technology produces relatively high levels of NOx, acidic gases, particulates, and metal waste. Incomplete combustion products can also leach into the soil and contaminate ground water from the burning pits used for open bum methods. The surrounding soil and ground water must often be remediated after OBOD to meet environmental guidelines. Conventional incineration methods can also be used to destroy munitions, but they require a relatively large amount of fuel. They also produce a significant amount of gaseous effluent that must be treated to remove undesirable components before it can be released into the atmosphere. Thus, OBOD and incineration methods for disposing of munitions become impractical owing to increasingly stringent federal and state environmental protection regulations. Further, today's ever stricter environmental regulations require that new munitions and weapon system designs incorporate demilitarization processing issues. Increasingly stringent EPA regulations will not allow the use of OBOD or excessive incineration techniques, so new technologies must be developed to meet the new guidelines.
Recovery and reuse methods, such as that of the present invention, are the most attractive alternative to the conventional destructive methods discussed above and can be used to recover, in an environmentally friendly way, substantially all of the munition components with very little waste generation. This state-of-the-art technology is feasible, safe, and relatively inexpensive. It also has the potential of meeting the recovery and reuse goals of demilitarization. Future demilitarization operations will be dominated by chemical conversion and recovery technologies that recover or convert the explosives and other components used in munitions manufacture to materials that can be recycled, or. resold, in a cost effective environmentally acceptable manner.
One type of explosive system that presents a demilitarization problem and in which the present invention can be practiced is bulk Composition B. That is Composition B that has not been loaded into a munition cavity, such as a shell casing. Composition B is a mixture comprised of 2,4,6-trinitrotoluene (TNT) and cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX) powder with a binder which is typically wax. It is desirable to separate the TNT from RDX from Composition B for demilitarization purposes. U.S. Pat. No. 5,977,354 to Spencer et al. teaches a method for recovering RDX from TNT in explosives such as Composition B, and Cyclotol by heating the explosive composition to melt the TNT, separately collecting and recovering the melted TNT. The thus separated RDX material is contaminated with minor amounts of TNT is treated with a solvent for TNT and a non-solvent for RDX to dissolve the TNT.
While the above Spencer patent presents an approach to recovering TNT from RDX there is never-the-less a need in the art for a continuous process for separately recovering TNT and RDX from bulk Composition B that contains RDX, TNT and a binder.